In a semiconductor device, semiconductor elements, which are heat generating parts, are mounted. The semiconductor elements generate heat and their temperature become high when the semiconductor device operates. In order to improve heat dissipation of the semiconductor device, a thick metal baseplate or a ceramic baseplate equipped with a circuit pattern is employed as a baseplate for the fixing semiconductor elements. A known configuration is that a fin base equipped with heat dissipating fins is joined to a metal baseplate by screw, to increase the heat dissipating area of the baseplate. An insulative silicone based resin material like grease is intercalated between the fin base and the metal baseplate.
A power semiconductor device with such a configuration needs a step of supplying a silicone-based material to the surface of a metal baseplate or a ceramic baseplate, or a heat dissipating member. Using a silicone-based material not only increases the number of manufacturing steps but also reduces the heat dissipation.
For example, Patent Document 1 is known as it discloses a technique without intercalation of a resin material, in which a ceramic baseplate is mounted on a fin-equipped metal base plate. The semiconductor device is entirely sealed with an epoxy resin. Patent Document 2 deals with a technology distinctive in fin manufacturing methods. Patent Document 3 is distinctive about structure of heat dissipating fins.